Generator



March 4, 1969 c, w so 3,431,444

GENERATOR Filed Dec. 14, 1966 INVENTOR,

C'urflls' L. 6.1175012 W 5M v ATTORNEYJ United States Patent 1 Claim Theinvention described herein may be manufactured and used by or for theGovernment, for governmental purposes, without the payment to me of anyroyalty thereon.

The present invention relates to a high speed, rugged electric generatorof simplified construction.

An object of the invention is a new and novel electric generator of lowweight and wherein the mass of the rotor thereof provides for faststarting and stopping as well as fast reversing of the rotation of saidrotor.

Another object of the invention is a compact lightweight electricgenerator wherein the fiux producing means and field coils arestationary.

A- still further object of the invention is a lightweight electricgenerator wherein a new and novel means is incorporated for admittingand cutting off the flux to the field coils whereby a voltage is inducedin the field coils.

The invention will be more fully understood and its objects andadvantages further appreciated by referring now to the followingdetailed specification taken in conjunction with the accompanyingdrawings in which:

FIGURE 1 is a longitudinal section of the generator to be described asan illustrative embodiment of the present invention,

FIGURE 2 is plan view of the disc rotor of the generator of the presentinvention.

FIGURE 3 is a view of one end of the generator.

Referring now to FIGURE 1, the reference numeral indicates a cylindricalshell which may be of non-magnetic material having afiixed to one end10a thereof by machine screws or any other suitable means an end cap 11of magnetic material such as iron so as to serve as a magnetic returnmember between rear ends of the cores 12 and 13 of the field coils 14and 15. The cores 12 and 13 are spaced 180 apart and have their rearends in threaded engagement with end cap 11. The opposite end 10b ofshell 10 is provided with an end cap 16 which may be of non-magneticmaterial and which may be fastened to end 10b by machine screws or byother suitable means. The end cap 16 is provided with two arcuate slots17 and 18 through which the arms 19 and 20 of the U-shaped permanentmagnet 21 pass and are rotatable therein. The permanent magnet 21 isrotatably mounted on the threaded stud 22 formed on end cap 16 andpositioned and re tained thereon by means of spacer 23 and nut 24,respectively. The arms 19 and 20 of permanent magnet 21 are in alignmentwith the field coils 14 and and spaced therefrom. A shaft 25 ofstainless steel or other material having low magnetic permeability isrotationally mounted in bearings 26 and 27 supported in end caps 16' and11, respectively, has a projecting part 28 which extends be yond end cap11 so that shaft 25 may be driven by mechanical power applied to pulley29 mounted thereon or any other coupling means.

A metallic disc 30 comprising the rotor of the gen- Patented Mar. 4,1969 erator is formed with pairs of equally spaced slots directedinwardly of the. peripheral surface of disc 30. For example, slots 34and 35 form a pair of slots along the y axis as shown in FIGURE 2.Reference numeral 38 indicates a central perforation in disc 30 toaccommodate the shaft 25. Disc 30 is mounted on shaft 25- and positionedthereon between the field coils 14 and 15 and arms 19 and 20 of thepermanent magnet for rotation therebetween. Disc 30 may be affixed toshaft 25 by means of flange 32 formed on the shaft and nut 33 or it maybe made integral with the shaft.

As can be seen by reference to FIGURE 1 of the drawings, maximum flux isobtained in the magnetic path formed between arm 19, field coil 14, endcap 11, field coil 15 and arm 20 when slots 34 and 35 or slots 36 and 37are in register with aforementioned arms and coils and minimum when asolid portion of the disc 30 is in register. In operation, the rotatingdisc 30* interrupts or chops the magnetic flux existing between the armsof the permanent magnet and the field coils thereby creating a varyingflux resulting in a voltage being induced in the field coils.

To provide for voltage control, permanent magnet 21 is rotatably mountedon stud 22 so that arms 19 and 20 may be angularly displaced, asindicated by reference numeral 21a, with respect to field coils 14 and15 whereby substantially all or a fraction of the flux emanating fromarms 19 and 20 may link the windings of the aforementioned field coils.

1 claim:

1. An electric generator comprising in combination a housing consistingof a cylindrical member, a first end cap of magnetic material providedwith a central perforation afiixed to one end of said cylindricalmember, first bearing means affixed in said perforation, a second endcap affixed to another end of said cylindrical member having a threadedboss formed centrally thereon and extending exteriorly thereof, secondbearing means supported by said second end cap within said housing andin alignment with said first bearing means, oppositely disposed arcuateslots formed in said second end cap, a U- shaped permanent magnetrotatably mounted on said threaded base with its two legs passingthrough said arcuate slots into interior of said housing, a first fieldcoil in said housing affixed to said first end cap and spaced from andin alignment with one of said legs, a second field coil in said housingaffixed to said first end cap and spaced from and in alignment with theother of said legs, a shaft rotationally mounted in said bearings havingone end extending exteriorly of said first end cap to which drivingpower is applied, a metallic disc provided with radial slots mounted onsaid shaft for rotation between said legs and said field coils, saiddisc upon rotation chopping the flux linking said legs and said fieldcoils whereby a voltage is induced in said field coils.

References Cited UNITED STATES PATENTS 1,401,883 12/1921 Crabb 310MILTON O. HIRSHFIELD, Primary Examiner.

L. ROUSE, Assistant Examiner.

1. AN ELECTRIC GENERATOR COMPRISING IN COMBINATION A HOUSING CONSISTINGOF A CYLINDRICAL MEMBER, A FIRST END CAP OF MAGNETIC MATERIAL PROVIDEDWITH A CENTRAL PERFORATION AFFIXED TO ONE END OF SAID CYLINDRICALMEMBER, FIRST BEARING MEANS AFFIXED IN SAID PERFORATION, A SECOND ENDCAP AFFIXED TO ANOTHER END OF SAID CYLINDRICAL MEMBER HAVING A THREADEDBOSS FORMED CENTRALLY THEREON AND EXTENDING EXTERIORLY THEREOF, SECONDBEARING MEANS SUPPORTED BY SAID SECOND END CAP WITHIN SAID HOUSING ANDIN ALIGNMENT WITH SAID FIRST BEARING MEANS, OPPOSITELY DISPOSED ARCUATESLOTS FORMED IN SAID SECOND END CAP, A USHAPED PERMANENT MAGNETROTATABLY MOUNTED ON SAID THREADED BASE WITH ITS TWO LEGS PASSINGTHROUGH SAID ARCUATE SLOTS INTO INTERIOR OF SAID HOUSING, A FIRST FIELDCOIL IN SAID HOUSING AFFIXED TO SAID FIRST END CAP AND SPACED FROM ANDIN ALIGNMENT WITH ONE OF SAID LEGS, A SECOND FIELD COIL IN SAID HOUSINGAFFIXED TO SAID FIRST END CAP AND SPACED FROM AND IN ALIGNMENT WITH THEOTHER OF SAID LEGS, A SHAFT ROTATIONALLY MOUNTED IN SAID BEARINGS HAVINGONE END EXTENDING EXTERIORLY OF SAID FIRST END CAP TO WHICH DRIVINGPOWER IS APPLIED, A METALLIC DISC PROVIDED WITTH RADIAL SLOTS MOUNTED ONSAID SHAFT FOR ROTATION BETWEEN SAID LEGS AND SAID FIELD COILS, SAIDDISC UPON ROTATION CHOPPING THE FLUX LINKING SAID LEGS AND SAID FIELDCOILS WHEREBY A VOLTAGE IS INDUCED IN SAID FIELD COILS.